ABSTRACT
The average yield of safflower blooming from 1 to 7 day was recorded and calculated, HPLC was used to detect the percentage composition of HYSA,quercetin,naringenin and kaempferol, and the real-time PCR was used to analyze the expression of chs and chi. The average yield,percentage composition of HYSA and naringenin as well as functional genes' expression presented similar trends. The average yield reached the highest peak at the third day, showing highpositive correlation with the contents of HYSA (r=0.756,P<0.05), and significant correlation with the expression of chi (r=0.892,P<0.01). The contents of naringenin showed a high positive correlation with the expression of chs(r=0.766,P<0.05). The study provides a theory basis for the composition and regulation mechanism of the flavonoid constituents and lays foundation for molecular mechanisms which lead to the difference of quality in C. tinctorius.